1. Field of the Invention
The present invention relates to a method of producing finely divided particles or powder, vapour or fine droplets and an apparatus therefor, and to a method for utilizing the products, and more particularly, relates to a method of producing finely divided particles or powder, vapour or fine droplets, and an apparatus therefor, and a method of producing products suitable for depositing or coating various metals, metal compounds, and ceramics, etc., on a surface of a base such as a steel sheet as used in a plating, flame spraying, CVD, PVD or spray formation process etc.
2. Description of the Related Art
As a method of producing such finely divided particles or powder, a method in which a metal such as iron or nickel is melted at a high temperature arc discharging portion in a hydrogen or nitrogen gas atmosphere and the molten metal is vapourized by the arc heating to deposit same on a wall surface, or a method in which vapour vapourized from the surface of a high temperature molten product by a high frequency melting process, are well known.
Further, a method disclosed in GB patent No. 1369585, in which oxidized finely divided particles are produced by heating the interior of a rotating hollow cylinder is also well known.
Nevertheless, none of these methods can realize a mass production of the divided finely particles or powder and a continuous use thereof as in the case of a continuous plating for forming a stacked coating layer on a steel sheet, etc.
Particularly, the GB Patent 1369585 discloses only a method of producing oxidized finely divided particles, i.e., an oxide and does not disclose a method of producing a non-oxide or nitride, etc.
Finely divided particles or powder, etc., are used to improve corrosion resistance wear-resistance (hardwearing) and a surface coloring, etc., by depositing or coating the products on a surface of a steel sheet, etc.
Where a product is deposited or coated on a base such as steel sheet, the manner of depositing coating or stacking an oxide thereon is important, and a non-oxide such as zinc, aluminum, or tin, etc., is generally deposited or coated on a surface of a base material using the oxide as a protecting film. This is because oxidation of a base material can be prevented by coating a protecting film which is more easily oxidized than the base material, at a non-oxidization state so that the protecting film is oxidized. This technology is known as a sacrifice corrosion resistance process.
Furthermore, by depositing, coating or coating-stacking a nitride such as TiN on the surface of the base material, the coloring property or the wear-resistance property thereof can be improved.
The current coating process has the following problems:
(1) In a conventional immersion plating process i.e., a senzimir process. The plating rate has a limit of 200 m/min due to the speed neck of a gas-wiping process for controlling the plating deposit.
(2) In a flame spraying process, the obtained coating layer is porous.
(3) In a CVD or PVD process the cost is increased as the coating thickness becomes larger.